Antonio “L.A.” Reid’s abrupt exit from Sony Music Entertainment's Epic Records followed a claim by a female assistant alleging “unlawful harassment of an employee,” sources tell Billboard. Sources said the claim prompted a company investigation into his conduct. The 60-year old music industry veteran allegedly made inappropriate physical advances toward an assistant at last December’s company holiday party, among other instances, according to a March 22 letter a lawyer for the woman sent to Julie Swidler, Sony Music’s General Counsel, said a source who provided details from the letter. The female assistant, whose name The Post is withholding, also claims Reid, who has led Epic for nearly six years, also asked her to lie down in bed with him and give him a hug while the two were at a hotel while traveling on business, the letter alleges. Reid, who is married, also made comments about what clothes he liked her to wear and described her as looking “fine,” the letter claims. Sony Music, in a one-sentence statement on Saturday — “L.A. Reid will be leaving the company” — confirmed the executive was on his way out. It did not elaborate. When asked about the complaints made in the letter, Sony Music on Sunday had no comment.