Maj Birtwistle, 48, was tipped for high promotion when she became pregnant 14 years ago and was dissuaded from considering a return after the baby was born, a tribunal in Manchester had was told earlier.
The payment, thrashed out after lawyers met behind closed doors for several hours, was the second highest agreed amount in such a case.
Solicitor Norman Lamb, chairman of an umbrella group representing claimants, said there were 5,500 cases where sex discrimination was claimed, most of which had been settled out of court.
But he said Maj Birtwistle's victory would not have any effect on those still outstanding.
"The reality is the vast majority are pretty modest levels," Mr Lamb, of the Armed Forces Pregnancy Dismissal Group, said. "Maj Birtwistle had a fine, flourishing career and the tribunal decision reflected the sort of person she was and the loss she suffered.
"But it is not of great significance in that tribunals will continue adopting the same criteria in the remaining cases, many of which involve those from the more lowly ranks and with a short period of service."
Maj Birtwistle, from Burton-in-Lonsdale, near Carnforth, Lancashire, had been described as "exceptionally employable" and had been tipped for promotion to full colonel by her senior officers.
She was the first woman ever to go on a Division One advanced weapons course and only the fourth to win a place at Army Staff College.
The tribunal said in its earlier ruling that being persuaded to resign when she became pregnant had deprived her of "the enjoyment, thrill and challenge of 20 or more years" with the Regular Army.
Maj Birtwistle, who now teaches statistics at Lancaster Prison, said: "A settlement has been reached at a figure which I named and one considerably less than that recently referred to in the press.
"Although I have received a large sum of compensation this case was never about money.
"No financial reward could ever fully compensate for the loss of a career which I dearly loved. Indeed my greatest desire was to obtain an order for my reinstatement in the army."
Only one servicewoman, from the RAF, has received a higher agreed settlement. The highest award imposed by a tribunal was pounds 350,000 to navy nurse Josephine Green, although lawyers are still negotiating the exact amount.
The tribunal chairman, Michael Homfray-Davies, said in his earlier ruling: "The anguish of the realisation that she could never return to her chosen and cherished career merits a high award."
Maj Birtwistle said: "I am deeply gratified by that description and I am grateful to the tribunal for the diligence and care with which they dealt with my claim."
Maj Birtwistle had originally submitted a claim for about pounds 750,000 for loss of earnings.Reuse content