A con artist on probation for embezzling more than $310,000 from her elderly, cancer-stricken ex-boss has now been charged with bilking four Midtown companies in a check scam, authorities said yesterday.

Elenie Felan, 28, had been employed as a clerk at four real-estate and construction companies — with access to their blank checks — when she launched her scheme in December, authorities claim.

She allegedly swiped at least eight checks, endorsed them and cashed them for a total of more than $4,000.

Last year, Felan pleaded guilty to grand larceny and was sentenced to five years probation after embezzling more than $310,000 from interior designer Joan Schindler, 80, whose clients have included Ralph Lauren and Dionne Warwick.