News of the disposals, which could be announced in the next few days, comes at a critical time for the company.
Earlier this week, Chris Greentree resigned as chief executive, sparking fears that Lasmo was planning to slash its final dividend for 1992 to shore up its weak balance sheet.
However, the expected disposals are likely to renew speculation that it may decide to hold the final payout of 6.2p a share.
The disposals are part of Lasmo's strategy to restructure its worldwide asset portfolio following its ill-fated pounds 1.1bn takeover of Ultramar two years ago.
It is understood the package includes Markham, the big gas field straddling British and Dutch waters, in which the company has a one-third stake. Sale of the field, which came into production late last year, could alone raise about pounds 100m for the company.
Other Lasmo blocks known to be up for sale include Bruce, Balmoral, Hutton, Forties and Ninian.
The company owns an interest in about 150 North Sea blocks - the second-biggest holding after British Petroleum. But it wants to concentrate on a smaller number of strategic blocks to improve efficiency and raise cash.
A spokeswoman for Lasmo said: ' We are looking at a number of assets as part of our continuing programme of disposals, but all I can say is that there will be a number of disposals during this year.'
Last month the company sold its interest in several North Sea blocks to various buyers for about dollars 120m. The deals took the total amount raised from disposals in 1992 to dollars 1.5bn, of which more than a dollars 1bn came from Ultramar's refining and shipping assets.
But despite the asset-stripping, the group's debts have remained high at about pounds 900m, amounting to 90 per cent of its net assets.
As a result, most City analysts expect that Lasmo will be fored to halve the dividend to bring its total payout for the year into line with earnings.
Lasmo shares closed 10p higher at 165p yesterday, more than recovering the 8p fall after Mr Greentree was ousted in a boardroom coup.
However, the shares were buoyed by stronger crude prices, a weakening sterling, and vague rumours that British Gas was preparing to launch a takeover bid.Reuse content