SEC probes share deals at Glazer's family firms

US financial regulators are investigating "mysterious movements" in the share prices of two companies controlled by the family of Malcolm Glazer, the billionaire who has said he may bid for Manchester United.

Mr Glazer, who owns the Tampa Bay Buccaneers American football team, has built a 16.8 per cent stake in the Premier League team, which was named the largest sports club in the world last week by accountants Deloitte.

He was forced to put out a statement last month clarifying his intentions at United, in which he admitted he might make an offer for the club. Mr Glazer is understood to have been advised by Mehmet Dalman of Commerzbank Securities and Keith Harris of Seymour Pierce.

He is now the second largest shareholder in United after Cubic Expression, the vehicle of the Irish racehorse owners JP McManus and John Magnier, which owns 29.8 per cent of the club.

On Friday, Mr Magnier settled a long-running dispute with United's manager, Sir Alex Ferguson, about the stud rights to the champion thoroughbred Rock of Gibraltar, paying £2.5m to Sir Alex. However, Cubic is retaining its stake in United and believes it is entitled to up to three seats on the board.

Mr Glazer's stake in United has cost him around £110m so far. Observers in the City have wondered how Mr Glazer, who dropped a $360m (£200m) offer for the LA Dodgers baseball club last year, would be able to pay for United, which is valued at nearly £700m.

Though the Tampa Bay Buccaneers, winners of the 2003 Super Bowl, are said to be worth more than $700m, the rules covering the ownership of teams in the US National Football League mean he cannot use his holding as collateral for a loan.

His main wealth comes from controlling stakes in two US public companies: Zapata, a holding company in which the Glazer family has 50 per cent of the stock, and Omega Protein, a fish oil maker in which Zapata has 60 per cent. Avram Glazer, Malcolm's son, is chairman of both companies, while Darcie Glazer, Malcolm's daughter, sits on both company boards.

An investigation by the US magazine Business Week has revealed that the Securities and Exchange Commission is probing sharp increases in the value of both Zapata and Omega stock in recent months, raising the value of the Glazer family investment by $50m. The movements tended to coincide with significant purchases of United stock by Malcolm Glazer, though there is no evidence they were linked.

The SEC is understood to have subpoenaed Theodore Roxford, a mysterious corporate raider who has admitted to being behind trading in Zapata shares, which sent them soaring from $22 a share in November 2002 to over $63 13 months later, and in Omega, where shares rose from under $6 to more than $8. John Held, the general counsel at Omega, has admitted that the SEC requested company documents late last year.

Neither Zapata nor any of the Glazer family was prepared to comment on the SEC investigation, although Avram Glazer has said in the past that neither he nor his father has had any dealings with Mr Roxford.