Former Morgan Stanley financial analyst Jennifer Wang and her husband Ruopian Chen - an ex-hedge fund analyst at ING - were each sentenced to a year-and-a-half in jail for insider trading, on Tuesday 4 December.

In an unusual twist to the case, US District Judge Colleen McMahon sentenced the couple to serve their sentences one after the other, to allow at least one of them to look after their infant son.

McMahon said her husband had worked for Morgan Stanley as an investment banker, and rejected a plea by one of the defence lawyers to not send Wang to jail, so she could be with her son. She said would not let Chen ''''take the fall for both'''', because Wang was more culpable.

Prosecutors said the couple traded in the securities of the Town and Country Trust, Glenborough Realty Trust and Genesis HealthCare, based on non-public information, from December 2005 to March 2007.

Glenborough was acquired by a Morgan Stanley affiliate in November 2006. Town and Country announced in late 2005 it would sell itself to investors led by units of Morgan Stanley and Onex Corporation of Canada. The couple conducted the trades in a brokerage account set up in the name of Wang''''s mother, who lives in Beijing.

Wang worked as a vice president in Morgan Stanley''''s finance department and Chen was a vice president at ING Investment Management Americas. The two resigned earlier this year from their respective employers.

On hearing the sentence, Wang wept silently. She will report to prison after Chen is released and their son has turned 2. The judge also ordered them to forfeit about $611,000. The New Jersey couple pleaded guilty to conspiracy and insider trading charges in September.

They were arrested in May and released on bail. Federal prosecutors accused them of trading based on material, nonpublic information that Wang obtained from Morgan Stanley, netting more than $600,000 from the scheme.

Wang''''s lawyer, Catherine Redlich, said she believed cultural differences may have played a factor. She said that in the People''''s Republic of China, insider trading, till very recently, wasn''t prosecuted as an offence. But the judge said she had herself worked as a lawyer and the only explanation she could come up with was greed: ''''You can''''t possibly not know that you are not allowed to do it,'''' she told them.