** Shares of industrial process heating firm Thermon THR.N jump 18.3% to $58.89 premarket after CECO Environmental CECO.O to buy co
** CECO says co to acquire THR in stock-and-cash deal worth $2.2 bln
** THR shareholders can opt for $63.89 per share in cash, or $10 in cash and 0.6840 CECO stock, or 0.8110 CECO shares per Thermon shares
** Cash offered by CECO is 28.4% premium to THR's last close
** THR says CECO to pay $105 mln if deal terminated
** Todd Gleason to continue as combined entity CEO
** CECO shares down 4.2%
** As of last close, THR up nearly 33.9% YTD, CECO up 29.8%
(Reporting by Utkarsh Tushar Hathi)
((utkarshtushar.hathi@thomsonreuters.com))