Television show "Access Hollywood" said host Billy Bush reached Trawick by text message, and the groom-to-be confirmed the news. "Yes, we are engaged," the show quoted Trawick as telling Bush.
Celebrity news magazine Us Weekly also reported the engagement, citing an unnamed source, saying Trawick popped the question at a private dinner on his 40th birthday, presenting the singer with a three-carat round stone and pave diamond ring. Website TMZ said the pair would be celebrating their engagement Friday night in Las Vegas.
Spears, 30, added fuel to the wedding fire with her own tweet Friday that said "OMG. Last night Jason surprised me with the one gift I've been waiting for. Can't wait to show you! SO SO SO excited!!!!"
Spears' spokesman did not return requests for comment.
The "Toxic" singer has been dating her former agent Trawick since May 2010, after a turbulent few years in her personal and professional life in which she lost custody of her children and was forced to enter rehabilitation after a public meltdown.
She was previously married to dancer Kevin Federline for two years, with whom she has two children. The singer also spontaneously married childhood friend Jason Alexander during a trip to Las Vegas in 2004. That marriage lasted 55 hours before the singer annulled the union.